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ABSTRACTA strategic sampling of eighteen counselors and counselors-in-training at different points in their professional development participated in a Q methodology design to help researchers better understand participants’ perspectives regarding their own development. The study was framed in the context of Rønnestad and Skovholt’s Lifespan Development Model (LDM). The analysis revealed three factors; two factors coincided with the LDM and one differed. Suggestions to stimulate and promote professional development are presented.

Growing up in religious/spiritual communities often creates identity issues for lesbian and gay individuals. In this phenomenological study, the authors investigated the experiences of 25 lesbian and gay individuals who self‐identified as having been raised within organized religious communities. Participants described that these communities were affirming, tolerant, or nonaffirming. Accordingly, emergent themes indicated that the current spiritual lives of participants varied greatly depending on their experiences of identity integration and affirmation. Implications for counselors and researchers are discussed.

Although identity is an important aspect of overall wellness, it is not yet understood how identity develops or how to accurately predict identity status. In this study of 192 emerging adult college students, the authors found that attachment, differentiation, and meaning-making subprocesses significantly predicted 3 of 4 identity statuses. Implications for counselors and counselor educators are discussed.

Skeletal muscle mitochondria are arranged as a reticulum. Insight into the functional characteristics of such structure is achieved by viewing the network as consisting of “subsarcolemmal” (SS) and “intermyofibrillar” (IMF) regions. During the decades, most, but not all, published studies have reported higher (sometimes over 2-fold) enzyme and enzyme-pathway protein-specific activities in IMF compared to SS mitochondria. We tested the hypothesis that non-mitochondrial protein contamination might account for much of the apparently lower specific activities of isolated SS mitochondria. Mouse gastrocnemii (n=6) were suspended in isolation medium, minced, and homogenized according to procedures typically used to isolate SS mitochondria. However, the supernatant fraction, collected after the first slow-speed (800g) centrifugation, was divided equally: one sample was exposed to nagarse (MITO+), while the other was not (MITO−). Nagarse treatment reduced total protein yield by 25%, while it increased protein-specific respiration rates (nmol O2min−1mg−1), by 38% under “resting” (state 4) and by 84% under maximal (state 3) conditions. Nagarse therefore increased the respiratory control ratio (state 3/state 4) by 30%. In addition, the ADP/O ratio was increased by 9% and the activity of citrate synthase (U/mg) was 49% higher. Mass spectrometry analysis indicated that the MITO+ preparation contained less contamination from non-mitochondrial proteins. We conclude that nagarse treatment of SS mitochondria removes not only non-mitochondrial proteins but also the protein of damaged mitochondria, improves indices of functional integrity, and the resulting protein-specific activities.

Fullscale tests of coldformed steel C and Zsection purlins supporting conventional throughfastened metalbuilding roof panels were tested under gravity loading. Both single and triplespan tests were conducted on each type of purlin. Test data is presented that indicates that fastener location affects the gravityload capacity of Csection purlins due to the location's effect on the torsional restraint supplied by the panels to the purlin. No effect of fastener location was noted on the capacity of Zsection purlins. Test data are also presented that indicate that the current edition of the AISI specification AISI: Specification1986 overpredicts the capacity of purlins with wide compressionflangestiffener lips.

The total creatine (TCr) pool of skeletal muscle is composed of creatine (Cr) and phosphocreatine (PCr). In resting skeletal muscle, the ratio of PCr to TCr (PCr/TCr; PCr energy charge) is ∼0.6–0.8, depending on the fiber type. PCr/TCr is linked to the cellular free energy of ATP hydrolysis by the Cr kinase equilibrium. Dietary Cr supplementation increases TCr in skeletal muscle. However, many previous studies have reported data indicating that PCr/TCr falls after supplementation, which would suggest that Cr supplementation alters the resting energetic state of myocytes. This study investigated the effect of Cr supplementation on the energy phosphates of resting skeletal muscle. Male rats were fed either rodent chow (control) or chow supplemented with 2% (wt/wt) Cr. After 2 wk on the diet, the gastrocnemius and soleus muscles were freeze clamped and removed from anesthetized animals. Cr supplementation increased TCr, PCr, and Cr levels in the gastrocnemius by 20, 22, and 17%, respectively (P< 0.05). A numerical 6% higher mean soleus TCr in Cr-supplemented rats was not statistically significant. All other energy phosphate concentrations, free energy of ATP hydrolysis, and PCr/TCr were not different between the two groups in either muscle. We conclude that Cr supplementation simply increased TCr in fast-twitch rat skeletal muscle but did not otherwise alter resting cellular energetic state.

VWA8 (Von Willebrand A Domain Containing Protein 8) is a AAA+ ATPase that is localized to the mitochondrial matrix and is widely expressed in highly energetic tissues. Originally found to be higher in abundance in livers of mice fed a high fat diet, deletion of the VWA8 gene in differentiated mouse AML12 hepatocytes unexpectedly produced a phenotype of higher mitochondrial and nonmitochondrial oxidative metabolism, higher ROS (reactive oxygen species) production mainly from NADPH oxidases, and increased HNF4a expression. The purposes of this study were first, to determine whether higher mitochondrial oxidative capacity in VWA8 null hepatocytes is the product of higher capacity in all aspects of the electron transport chain and oxidative phosphorylation, and second, the density of cristae in mitochondria and mitochondrial content was measured to determine if higher mitochondrial oxidative capacity is accompanied by greater cristae area and mitochondrial abundance. Electron transport chain complexes I, II, III, and IV activities all were higher in hepatocytes in which the VWA8 gene had been deleted using CRISPR/Cas9. A comparison of abundance of proteins in electron transport chain complexes I, III and ATP synthase previously determined using an unbiased proteomics approach in hepatocytes in which VWA8 had been deleted showed agreement with the activity assays. Mitochondrial cristae, the site where electron transport chain complexes are located, were quantified using electron microscopy and stereology. Cristae density, per mitochondrial area, was almost two-fold higher in the VWA8 null cells (P < 0.01), and mitochondrial area was two-fold higher in the VWA8 null cells (P < 0.05). The results of this study allow us to conclude that despite sustained, higher ROS production in VWA8 null cells, a global mitochondrial compensatory response was maintained, resulting in overall higher mitochondrial oxidative capacity.

Dietary iron deficiency (ID) decreases iron-containing proteins and hence respiratory capacity of skeletal muscle mitochondria (SMM), but noniron components are much less affected. Using a hexokinase plus glucose ATP-utilizing system, we studied control of respiration in isolated SMM from rats of variable iron status: ID, ID 3 days after intraperitoneal treatment with iron dextran, and control. We found that sensitivity of respiratory control (e.g., ATP/ADP at a given oxygen consumption) was positively related to state 3 respiratory capacity. Titration studies with carboxyatractyloside, a noncompetitive inhibitor of adenine nucleotide translocase (AdNT), revealed that AdNT concentration was unaffected by iron status. However, the turnover number of AdNT was markedly reduced by ID and improved with iron treatment. We conclude that in ID SMM, decreased maximal respiratory capacity is paralleled by impaired sensitivity to putative controllers of oxidative phosphorylation at any respiratory rate, despite normal levels of AdNT. A second study was designed to determine possible consequences of impaired sensitivity of respiratory control on motor unit recruitment during exercise. ID and normal rats were subjected to a program of walking treadmill exercise. Although exercise failed to induce any changes in oxidative enzyme levels in control rat, ID animals and exhibited substantial mitochondrial enzyme adaptation in hindlimb skeletal muscle. Furthermore, the most consistent enzymatic changes were observed to occur in fast glycolytic muscle fibers. These results suggest marked alterations in the pattern of muscle fiber recruitment during mild exercise in ID rodents and support the hypothesis that sensitivity of respiratory control in SMM is an important determinant of motor unit recruitment during aerobic exercise.

Full‐scale tests of cold‐formed steel C‐ and Z‐section purlins supporting conventional (through‐fastened) metal‐building roof panels were tested under gravity loading. Both single‐ and triple‐span tests were conducted on each type of purlin. Test data is presented that indicates that fastener location affects the gravity‐load capacity of C‐section purlins due to the location's effect on the torsional restraint supplied by the panels to the purlin. No effect of fastener location was noted on the capacity of Z‐section purlins. Test data are also presented that indicate that the current edition of the AISI specification (AISI: Specification 1986) overpredicts the capacity of purlins with wide compression‐flange‐stiffener lips.

SPECTOR, S. A., M. R. JACKMAN, L. A. SABOUNJIAN, C. SAKKAS, D, M. LANDERS, and W. T. WILLIS. Effect of choline supplementation on fatigue in trained cyclists. Med. Sci. Sports Exerc., Vol. 27, No. 5. pp. 668–673, 1995. The availability of choline, the precursor of the neurotransmitter, acetylcholine, in the diet is sufficient to provide the body's requirements under normal conditions. However, preliminary evidence indicates that depletion of choline may limit performance, while oral supplementation may delay fatigue during prolonged efforts. A double-blind cross-over design was used to determine the relationship between plasma choline and fatigue during supramaximal brief and submaximal prolonged activities. Twenty male cyclists (ages 23–29) with maximal aerobic power (VO2max) between 58 and 81 ml·min-1·kg-1were randomly divided into BRIEF (N= 10) and PROLONGED (N= 10) groups. One hour after drinking a beverage with or without choline bitartrate (2.43 g), cyclists began riding at a power output equivalent to approximately 150 (BRIEF) and 70 (PROLONGED) of VO2maxat a cadence of 80–90 rpm. Time to exhaustion, indirect calorimetry and serum choline, lactate, and glucose were measured. Increases in choline levels of 37 and 52 were seen within one hour of ingestion for BRIEF and PROLONGED groups, respectively. Neither group depleted choline during exercise under the choline or placebo conditions. Fatigue times and work performed under either test condition for the BRIEF or PROLONGED groups were similar. Consequently, trained cyclists do not deplete choline during supramaximal brief or prolonged submaximal exercise, nor do they benefit from choline supplementation to delay fatigue under these conditions.

This paper offers a brief synopsis of the five preceding papers which constitute the proceedings of the symposium “Mechanistic basis of the slow component of O2kinetics during heavy exercise.” The key features have been taken from each paper and a coherent position regarding the site and potential underlying mechanisms for the “excess” O2is presented. The hypothesis is developed that some aspect of fiber type recruitment patterns might be responsible for this phenomenon. Elucidation of the precise determinants of O2during heavy exercise is fundamental to our understanding of muscle energetics. Furthermore, certain patient populations, whose exercise tolerance is limited by impaired cardiovascular and/or respiratory capacity, may benefit from interventions designed to constrain the magnitude of the O2slow component.

Maximal rates, coupling, and control of oxidative phosphorylation were studied in isolated skeletal muscle mitochondria from rat and rabbit. Mitochondria were incubated under various conditions of temperature, pH, and substrate availability. A 20 decrease in coupling (ADP/O) was observed at 43°C as compared to 37°C in rat mixed skeletal muscle mitochondria. Changes in pH from 7.00 to 6.20 affected neither coupling nor maximal (state 3) respiration rates. Changing the substrate supply from pyruvate to palmitoyl-carnitine ( malate) did not alter ADP/O, but markedly degraded the energy state sustained at submaximal ATP turnover. Thus, carbohydrate depletion may be associated with inhibition of contractile function and the recruitment of less economical higher threshold motor units. State 3 respiration of mitochondria from rabbit Type IIb fibers oxidizing pyruvate malate α-glycerophosphate was 27 higher than that of mitochondria from Type I rabbit skeletal muscle. However, the ADP/O ratio in the Type IIb preparation was 18 lower. The experimental findings suggest that temperature, substrate supply, and energetic differences between slow twitch and fast twitch motor units may impact the economy of mitochondrial oxygen utilization during heavy aerobic exercise, and thus contribute to the slow component of oxygen uptake.